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New Power Cylinder and Piston
Information on this article is still being worked on.
Please be patient.
I wanted to show what was being worked on now rather then waiting.

    A lot of people are having problems finding material to make the power piston and cylinder. So I have been working on a possible alternative that needs no lathe and a minimum of power tools.

The New Power Cylinder

     Below is how to make the cylinder and where to get parts. Please keep in mind I was not trying to keep the price down, but instead give you and alternative that was easy.

Please refer to the photo below:

From Left to right

1)   1/8" to 1/4" brass bushing
       This fitting can be found in any hardware store.

2)    1/4" to 3/4" Steel bushing (brass would be OK also, just more expensive)
        This fitting can be found in any hardware store.
        The 1/4" (small inside) must be tapped larger with a 1/4" NPT (pipe thread)
        tap. The threads on pipe taps are tapered. By running it in deeper it allows
        the bushing above to thread all the way in.

3)     Bronze Sleeve Bearing for 1" Shaft Diameter, 1-1/4" OD, 3" Long 
        McMaster Carr
        Bearing # 6381K217.  Price $4.97 each
        Page #1005 in their cataloge. Just do a search for 6381K217

        This bearing has to be threaded on one end only with a 3/4" NPT
        (pipe thread) tap. Not too far or you wont't have enought cylinder
        free in the inside. If this happens, Just grind down the end of the
        1/4" to 3/4" bushing so it don't go in as deep.

Here is how it is installed onto the
Displacer Cylinder

Use Hi Temp silicone sealer when installing it on the displacer cylinder
to seal leake. Hi Temp silicone can be bought at any automotive parts store.
It's the red stuff they put on gaskets.  Also use it on the theads of the larger
bushing into the bronze cylinder to seal the threads so they don't leak.

Now the New Piston

I used aluminim stock ordered from McMaster Carr
Alloy 6061 Aluminum Rod 1" Diameter, 3' Length (min length)

$15.83 Each

I know this is a lot to pay, but I hope to be offering 3/4" long pieces
soon at cost and this will be easier.

The rod will have to be sanded slightly as it is a tight fit in the cylinder above, but
It is very easy to do and get right.

I still need to get photos of the process and how
to machine the piston using a drill motor

Coming Soon!

PS, I will be needing a person willing to try this new cylinder and piston out
when I'm done with it.

Changes To The Original Plans

Keep That Displacer Piston On!

This came to me when asked the question what to do about a displacer piston that has fallen off the
rod inside the cylinder by Joseph Simone in an email.
By adding a "Hook" to the end of the 1/8" rod on the
displacer piston, In the event you "over heat" the engine the displacer piston will not fall off inside the displacer cylinder.
In other words, You won't have to "tear the entire engine apart if a "over heat" happens.
This is what happened to the "Computerized Stirling Engine".

The Haigh piston

This is a possible alternative to a lathe turned piston or a brake piston.

The following is an email sent to me by Dan Haigh

Thought I'd pass on a hint for those folks who don't have a lathe, but want to make pistons to fit 1" Type M copper pipe.  Since both Type M (1.055" I.D.) and Type L
(1.025" I.D.) are readily available in most areas, here's what I did: 

I cut a 3/4" long piece of Type L using a tubing cutter and carefully deburred the inside of both ends (a jackknife works fine).  I then coated the inside with a thin
coating of grease and set it on a sheet of silicone rubber gasket material.  The 3/4" cylinder was then filled to 1/8" from the top with mixed, 2-part epoxy (I used a
product called "J-B Weld" because it makes a fairly thick mix that won't leak out and it's good to 600 degrees F.).  I then suspended a short (about 1") piece of 1/4" X
1/32" brass bar stock (with a 9/64" hole for the connecting rod) centered in the mix.  A small alligator clip works fine for holding the bar stock in place while the epoxy

I let the epoxy cure overnight, then pressed out the finished piston with a bearing press.  If a bearing press or strong drill press isn't available, the piston can be removed
by carefully cutting through the copper pipe section with a hacksaw and prying it apart. 

The resulting lightweight piston will need a very minor amount of sanding on the leading edge and then will fit beautifully into Type M copper pipe.  I know the above
directions are a bit confusing, so I'm attaching a sketch of what I mean. 

Best regards, 
Dan Haigh 

Oiling Tip/Change

Power Piston Oiling. Allows oiling during running.

How to Drill that bolt at the top of the displacer piston!
As they say " A picture is worth a thousand words", here is 3 thiousand words!
Thanks to Matt Engelber for this idea




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